Metal substrates used in industrial applications and as parts in vehicular or other engine and exhaust systems are routinely subjected to extreme high temperatures, which over time may lead to fatigue, cracking, distortion, and other failures of the substrate. For example, components near an automotive exhaust system can be exposed to temperatures in excess of 400° C. In such a situation, it is readily apparent that fatiguing or cracking can lead to catastrophic failure. Insulating an automotive floor pan is especially challenging when the distance between the exhaust system and the floor is reduced, as in more compact cars. Conventionally, the automotive industry inserts aluminum sheet between the exhaust system and the floor-pan to deflect and insulate, with air gap or insulation pads between the aluminum sheet and floor-pan. This method has high manual labor costs and requires extra spacing between the exhaust system and the floor-pan.
In addition to heat reflection sheets, barrier, sealants and sound dampeners typically are applied to a variety of areas in automobile bodies such as interior floor pans, firewalls, decklids, and between the inner and outer panels of doors. Conventionally, sealants have comprised plastisols that can be applied between and upon metal seams, welds and within hollow cavities of auto bodies. Generally, sealants are used to impart structural integrity and to create a barrier against dirt, moisture, and exhaust gases. Sound dampeners typically are pre-cut pieces of fibrous asphaltic material, Liquid Applied Sound Damper (LASD) or aluminum constrained butylene rubber used to dampen road and engine noise that can be transmitted through the auto body substrates.
Conventionally, sealants and sound dampeners are applied to some automotive parts in the paint shop area of an automobile assembly plant which is typically located downstream from the electrocoat tank in the automotive coating process. The manual application of sealants and sound dampeners in the paint shop area can result in fingerprints, dirt and/or overspray on the automotive part which must be removed prior to subsequent application of primer and/or top coatings. Robotically applied LASD eliminates these defects and need for cleaning stage. It would be advantageous if robotically applied LASD has multifunctional properties, such as heat insulation properties, and sound absorption properties in addition to the vibration damping, especially on the floor pan above the exhaust system and the firewall area.
It would further be desirable to provide heat reflective, curable film-forming compositions applied to the opposite side of the substrate facing exhaust system or the engine compartment that can minimize the heat passing through the substrate, eliminating the need for manually inserted sheets and pads and thereby saving space between the exhaust system and the floor-pan.